In recent years, intraorally rapidly disintegrating tablets have attracted attention as the form of a preparation for improving the ability of a chemical to be administered, thus improving patient's compliance etc., and various tablets have been invented.
In consideration of excellent solubility in the mouth, many of conventional intraorally rapidly disintegrating tablets comprise sugar alcohols such as mannitol and xylitol as excipients. However, sugar alcohols easily cause obstacles such as sticking (adhesion to a punch) and binding (adhesion to a die) at the time of tabletting, and hardness is hardly secured. Accordingly, when intraorally rapidly disintegrating tablets are produced by using sugar alcohol as an excipient, a special process and a special apparatus have been employed wherein, for example, a mixture containing sugar alcohol is first moistened suitably with water, then compression-molded under low pressure, dried and thus tabletted.
On the one hand, production of intraorally rapidly disintegrating tablets, which is as close as possible to a usual method of producing tablets by tabletting dry powder or granules, is also devised. For example, a method of producing intraorally rapidly disintegrating tablets which comprises compression-molding a mixture containing a medicament and a disintegrating agent with fine sugar alcohol or sugar having an average particle diameter of 30 μm or less as a major ingredient (see WO 97/47287) and a method of producing intraorally rapidly disintegrating tablets which comprises compression-molding a major ingredient sugar alcohol or sugar not particularly fine, to which a disintegrating agent and cellulose were added (see JP-A 2001-58944), have been anticipated.
However, the techniques described above are common in that dry sugar alcohol is used as a major ingredient, and thus there is necessity for an increase in the content of a highly water-repellent lubricant and for limitation of compression pressure, in order to prevent sticking and binding, and there is a limit to disintegrating properties and hardness.